TrapezoidProfile Class Reference

#include <trapezoid_profile.h>

Public Member Functions
	TrapezoidProfile (double max_v, double accel)
	Construct a new Trapezoid Profile object.
motion_t	calculate (double time_s)
	Run the trapezoidal profile based on the time that's ellapsed.
void	set_endpts (double start, double end)
void	set_accel (double accel)
void	set_max_v (double max_v)
double	get_movement_time ()

Detailed Description

Trapezoid Profile

This is a motion profile defined by an acceleration, maximum velocity, start point and end point. Using this information, a parametric function is generated, with a period of acceleration, constant velocity, and deceleration. The velocity graph looks like a trapezoid, giving it it's name.

If the maximum velocity is set high enough, this will become a S-curve profile, with only acceleration and deceleration.

This class is designed for use in properly modelling the motion of the robots to create a feedfoward and target for PID. Acceleration and Maximum velocity should be measured on the robot and tuned down slightly to account for battery drop.

Here are the equations graphed for ease of understanding: https://www.desmos.com/calculator/rkm3ivu1yk

Author

Ryan McGee

Date

7/12/2022

Constructor & Destructor Documentation

TrapezoidProfile()

TrapezoidProfile::TrapezoidProfile	(	double	max_v,
		double	accel )

Construct a new Trapezoid Profile object.

Parameters

max_v	Maximum velocity the robot can run at
accel	Maximum acceleration of the robot

Member Function Documentation

calculate()

motion_t TrapezoidProfile::calculate

(

double

time_s

)

Run the trapezoidal profile based on the time that's ellapsed.

Parameters

time_s

Time since start of movement

Returns

motion_t Position, velocity and acceleration

get_movement_time()

double TrapezoidProfile::get_movement_time

(

)

uses the kinematic equations to and specified accel and max_v to figure out how long moving along the profile would take

Returns

the time the path will take to travel

set_accel()

void TrapezoidProfile::set_accel

(

double

accel

)

set_accel sets the acceleration this profile will use (the left and right legs of the trapezoid)

Parameters

accel

the acceleration amount to use

set_endpts()

void TrapezoidProfile::set_endpts	(	double	start,
		double	end )

set_endpts defines a start and end position

Parameters

start	the starting position of the path
end	the ending position of the path

set_max_v()

void TrapezoidProfile::set_max_v

(

double

max_v

)

sets the maximum velocity for the profile (the height of the top of the trapezoid)

Parameters

max_v

the maximum velocity the robot can travel at

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The documentation for this class was generated from the following files:

• trapezoid_profile.h
• trapezoid_profile.cpp